2.2.6

Release notes

• update ext/mbedtls to 2.28.2 and rebuild lib
• zone1: fix lwip thread wfi timeout and add "restart" msg
• update arty7 .mcs release files and README.md links
• hexfive-conf @7a9dd5 (v2.2.6)
• hexfive-ker @261971 (v2.2.6)

Security

• https://github.com/Mbed-TLS/mbedtls/releases/tag/v2.28.2

• Fix potential heap buffer overread and overwrite in DTLS if
  MBEDTLS_SSL_DTLS_CONNECTION_ID is enabled and
  MBEDTLS_SSL_CID_IN_LEN_MAX > 2 * MBEDTLS_SSL_CID_OUT_LEN_MAX.

• An adversary with access to precise enough information about memory
  accesses (typically, an untrusted operating system attacking a secure
  enclave) could recover an RSA private key after observing the victim
  performing a single private-key operation if the window size used for the
  exponentiation was 3 or smaller. Found and reported by Zili KOU,
  Wenjian HE, Sharad Sinha, and Wei ZHANG. See "Cache Side-channel Attacks
  and Defenses of the Sliding Window Algorithm in TEEs" - Design, Automation
  and Test in Europe 2023.